Numerous proposals have been made for ramps that may extend outwardly from the tailgate of a pick-up truck. U.S. pat. Nos. 4,628,561; 4,144,335; 5,312,149; and 5,536,058 all describe telescopically collapsible ramps. Examples of foldable ramps are U.S. Pat. 3,6741,156, 4,517,941 and 4,864,673.
To effect storage of the ramp after the vehicle is loaded, it has been proposed to provide the pick-up truck box with a second, elevated floor so that the entire ramp may be slid into the space beneath this floor.
Generally, these ramps have a pair of outside stringers with rungs extending therebetween. In many cases the rungs are fixed to the risers. In U.S. Pat. No. 4,290,728 the rungs are free to slide along the risers, being linked when deployed by lengths of chain that cause them to be evenly spaced along the length of the ramp. In this latter case the ramp is stored by assembling the rungs as a bundle at the tailgate end of the truck box and the risers are slid separately into the truck box on either side of the load. Thus, the ramp is not stored in a readily deployable format.
It is desirable to provide a loading ramp for a vehicle that is low in cost to manufacture, may be readily deployed and may be stored conveniently in the cargo area of the vehicle which the ramp serves. This invention addresses those objectives.
The invention in its general form will first be described, and then its implementation in terms of specific embodiments will be detailed with reference to the drawings following hereafter. These embodiments are intended to demonstrate the principle of the invention, and the manner of its implementation. The invention in its broadest and more specific forms will then be further described, and defined, in each of the individual claims which conclude this Specification.